Agar

solidifying agent, is a purified agar in which extraneous matter, pigmented portions and salts are reduced to a minimum. It is available in the form of fine, light colored granules which are convenient for weighing and handling. It is usually used in concentrations of 1-2% in solid culture media or in concentrations of 0.05%-0.5% in media used for determination of motility and the growth of anaerobes and microaerophiles.